Irrespective of the precise mechanism of the vascular calcific deposits, it is clear that chronic hypercalcemia is detrimental to the vascular system and that its effect, at least in adults, is worsened by the presence of hypercholesterolemia, and possibly also by the presence of systemic hypertension. Additional support for the role of hypercalcemia in causing vascular and nonvascular calcific deposits comes from studies of chronic hypervitaminoisis D in infants and children, and from its association with the congenital syndrome of peculiar elfin faces, mental retardation, and supravalvular aortic stenosis. The present study also strongly suggests that chronic hypercalcemia is a "risk factor" to premature coronary atherosclerosis, especially in patients with an elevated serum cholesterol.